The present invention relates, in general, to channel coding operations, and more particularly to reconfigurable channel coding operations to accommodate various wireless communication standards.
The use of cellular telephones in today""s society has become widespread. While facilitating communication in a myriad of environments, the various existing and emerging wireless standards inhibit the ability to utilize a single device across the standards and platforms. The inability to have cross-platform coverage in a single device is due in large part to the inability to provide a hardware solution that can be adapted to varying standards.
For example, in terms of the channel coding operations that are necessary, existing and emerging wireless standards utilize myriad error mitigation techniques to operate in a hostile channel environment. Existing standards utilize two levels of coding plus block interleaving to address both single error and burst error phenomena. Group codes are used for the outer codes, and convolutional codes are used for the inner codes of the various concatenated coding schemes. No two standards employ the same combination. Additionally, certain standards employ encryption to offer a degree of privacy and security.
Utilization of an ASIC (application specific integrated circuit) approach for channel coding would be inefficient in such an environment, since there would need to have individual ASICs for supporting each possible standard. In addition, there would be an ongoing requirement to support modifications from an original design without the ability of having new silicon. A RISC (reduced instruction set computing) option is inefficient for the bit-oriented operations required for channel coding. Similarly, a DSP (digital signal processing) approach is also ill-suited to the bit-oriented requirements of channel coding. Use of a microprogrammed approach provides an arcane nature of programming and maintaining that precludes serious consideration as a solution. While FPGAs (field programmable gate arrays) do provide flexibility, the high costs, both in transistor count and control overhead, outweigh their benefits.
Accordingly, a need exists for a channel coding approach that allows convenient, efficient, and effective support across multiple standards. The present invention addresses such a need.
Aspects of a reconfigurable system for providing channel coding in a wireless communication device are described. The aspects include a plurality of computation elements for performing channel coding operations and memory for storing programs to direct each of the plurality of computation elements. A controller controls the plurality of computation elements and stored programs to achieve channel coding operations in accordance with a plurality of wireless communication standards. The plurality of computation elements include a data reordering element, a linear feedback shift register (LFSR) element, a convolutional encoder element, and a Viterbi decoder element.
With the present invention, a reconfigurable channel coder is provided that minimizes point designs, i.e., the present invention avoids designs that satisfy a singular requirement of one, and only one, wireless standard, which would render them useless for any other function. Further, bit-oriented operations of channel coding are successfully mapped onto a set of byte-oriented memory and processing elements. In addition, the present invention achieves a channel coder in a manner that provides realizability, reliability, programmability, maintainability, and understand-ability of design, while gaining savings in power and die area. Numerous other advantages and features of the present invention will become readily apparent from the following detailed description of the invention and the embodiments thereof, from the claims and from the accompanying drawings.